Wednesday, January 27, 2010

I guess some time in the last few months, I updated udev on my Gentoo Xen Guest. Normally, this wouldn’t be a problem and it wasn’t since I didn’t need to reboot the system until yesterday. It wouldn’t come back up automatically, so I consoled the domain with xm, and saw this:

* Mounting proc at /proc ... [ ok ]
* Mounting sysfs at /sys ... [ ok ]
* Your kernel is too old to work with this version of udev.
* Current udev only supports Linux kernel 2.6.25 and newer.
* Could not create /dev/pts!
* Checking root filesystem ...Failed to open the device '/dev/hda2': No such file or directory
* Filesystem couldn't be fixed :(
[ !! ]
Give root password for maintenance
(or type Control-D to continue):

Of course I didn’t read the obvious error at first, and started messing around with other things before finally realizing the kernel the Xen domain is booting from is still at version 2.6.18. I had two options:
1) upgrade the domu kernel from xen-sources (>2.6.18-r12 still being masked on this system) and copy it to the xen host for the vm to boot from.
2) downgrade udev and pretend it never happened.

I chose #2, mainly because it’d take less time and work.
In short, here’s what I did:Note: This is all from root on the Xen Dom0, not the guest machine.. since it wouldn’t boot yet.

Sunday, November 1, 2009

I always forget little things like this. Today I changed the dyndns hostname I’ve been using on a server, and needed to update my Apache vhost .conf file to reflect the new domain. There’s only about 10-15 virtual hosts in this file, but I still didn’t want to manually edit it. I’m lazy.

vim 90_bac.supercoolname.tld.conf

Once you’re in vim, it’s super-easy to do a find and replace. This is the command I ran:

%s/bac.supercoolname.tld/bac.evenbettername.tld/g

%s tells vim to search through the entire file.

/g tells vim to replace every instance of bac.supercoolname.tld with bac.evenbettername.tld

There’s a ton of other useful stuff you can do with regular expressions, but this is something I forget a lot when I don’t use it frequently.

Thursday, July 16, 2009

In case you’re not aware, Nmap’s a free/open-source network scanner, and this is the first major release in quite some time. I’m installing it now and will update when I get a chance to try some of the new features out 🙂

Head over to their website for a detailed list of the changes, but here’s the top 5 improvements(as listed by them) :

The new Ncat tool aims to be your Swiss Army Knife for data transfer, redirection, and debugging. We released a whole users’ guide detailing security testing and network administration tasks made easy with Ncat.

The Nmap Scripting Engine (NSE) is one of Nmap’s most powerful and flexible features. It allows users to write (and share) simple scripts to automate a wide variety of networking tasks. Those scripts are then executed in parallel with the speed and efficiency you expect from Nmap. All existing scripts have been improved, and 32 new ones added. New scripts include a whole bunch of MSRPC/NetBIOS attacks, queries, and vulnerability probes; open proxy detection; whois and AS number lookup queries; brute force attack scripts against the SNMP and POP3 protocols; and many more. All NSE scripts and modules are described in the new NSE documentation portal.

We released Nmap Network Scanning, the official Nmap guide to network discovery and security scanning. From explaining port scanning basics for novices to detailing low-level packet crafting methods used by advanced hackers, this book suits all levels of security and networking professionals. A 42-page reference guide documents every Nmap feature and option, while the rest of the book demonstrates how to apply those features to quickly solve real-world tasks. More than half the book is available in the free online edition.

The addition of the Ndiff scan comparison tool completes Nmap’s growth into a whole suite of applications which work together to serve network administrators and security practitioners. Ndiff makes it easy to automatically scan your network daily and report on any changes (systems coming up or going down or changes to the software services they are running). The other two tools now packaged with Nmap itself are Ncat and the much improved Zenmap GUI and results viewer.

Nmap performance has improved dramatically. We spent last summer scanning much of the Internet and merging that data with internal enterprise scan logs to determine the most commonly open ports. This allows Nmap to scan fewer ports by default while finding more open ports. We also added a fixed-rate scan engine so you can bypass Nmap’s congestion control algorithms and scan at exactly the rate (packets per second) you specify.

Thursday, June 4, 2009

I came across this piece of [old] news at CIO. Apparently IBM is working on a new super computer code-named “Watson”. They’re trying to take Artificial Intelligence to the next level with this machine, and think it’ll be capable of competing with humans on game shows like Jeopardy.

“Watson, in its final stages of development, is a question answering system that has been in development for nearly two years. Underneath Watson’s hood, natural language processing and other technologies analyze meanings behind words. This gives Watson the ability to identify relevant and irrelevant content, interpret ambiguous expression and puns, decompose questions into sub-questions, and synthesize information to form an answer, IBM says. Watson considers massive volumes and varieties of natural language, then quickly analyzes and scores supporting or refuting evidence—in a matter of seconds.”

With Wolfram Aplha out now and Google Squared in the works, it seems like there’s actually quite a bit of work going on with AI-ish programs lately. I’m looking forward to hearing more about AI development.

Apparently eggdrop has some issues with SSL on 64 bit systems, but Egghelp has a few patches to fix this. eggdrop 1.6.19 has been out since April, but the ebuilds in Gentoo Portage haven’t been updated yet for whatever reason so I took it upon myself to update my own ebuild and share it here.

Note: I did find this gentoo bug for a version bump. This is where the eggdrop-1.6.19-patches-1.0.tar.bz2 file came from with all of the patches.

How to install the eggdrop-1.6.19 ebuild?

If you already have a local portage overlay set up, ignore step 1 & 2. Otherwise, we need to create a portage overlay directory and add it to make.conf.

After we extract it, delete the tarball and copy the patches to the distfiles directory
[code]rm -f eggdrop-1619-tstar.bz2 ; cp -v files/eggdrop-1.6.19-patches-1.0.tar.bz2 /usr/portage/distfiles/[/code]

You’ll probably need to add eggdrop to your package.keywords file now, so change amd64 to whatever keyword you would normally use on your system (Note: I only added it specifically for this version)
[code]echo “=net-irc/eggdrop-1.6.19 ~amd64” >> /etc/portage/package.keywords[/code]

Now, emerge!
[code]emerge -av eggdrop[/code]

If you haven’t used eggrop before, then you’d want to log in as the user you’re planning to run it on then run ‘eggdrop-installer’

Thursday, November 27, 2008

I’ve been using mozilla thunderbird a lot more lately, mainly because of work. It’s always bugged me that it doesn’t minimize to the tray by default.

It’s probably fairly obvious, but I ended up searching google for a little while and stumbling across old versions of a plugin meant to minimize thunderbird to the windows system tray. I should have just looked on mozilla’s website to begin with 🙂

To help someone else out when searching for “how to minimize thunderbird to tray”, go download the following extension: